With 96 different fields, Honda’s program enables fine-tuning,
but it takes a long time to implement those changes.
assumed we could get the previous power back with the mapping tool. We were right. Q: HOW CAN I GET 2009 CRF450 MAPPING INTO MY 2010? A: You can’t actually do it. Honda changed more than what the program will allow you to do. You can achieve a similar feel with a mapping change, but not the exact same settings. If you wanted to, you could replace the 2010 ECU with a 2009 unit. Q: WHAT IS THE DIFFERENCE BETWEEN THE STOCK MAPPING OF THE 2010 CRF450 AND THE 2009 CRF450? A: Honda says this information is classified. A fuel injector is much more complicated than you may realize. It responds to information from many sensors (like coolant temperature, intake air temperature, manifold pressure, throttle position sensor and crank position sensor) to precisely adjust fuel and ignition timing for optimum power delivery in varying weather, altitude and load conditions. When Honda engineers figured out tricks to get their injectors to work well, the higher-ups at the factory in Japan nixed the idea of sharing their exact settings with the world. After some probing, they did tell us some of the areas in which they made changes. Honda tweaked injector stage timing, transient variables and BOI (Beginning Of Injection), and the variables relat- ed to starting have been matched to the new cam/decompression system. The fuel and ignition timing have been slightly changed to work with the new cam/decompression system as well. Q: WHAT DO ALL THOSE FANCY PHRASES MEAN? A: Here are some parameters of a motocross bike’s fuel-injection setup. Fuel timing: Since the pressure and the size of the injector nozzle are constant, the amount of fuel delivered depends on the duration of time it is squirted—called pulse width. The duty cycle is the percentage of time the injector is switched on in relation to engine cycles. Transient fuel: This is the electronic version of an accelerator pump. It relies on throttle position to multiply fuel by some factor. If the factor is 1.5, it would add 50 percent to the normal amount of fuel over a certain number of engine cycles. Decay time: This is how many engine cycles transient fuel lasts. Decay rate: This is how quickly the transient fuel factor is brought back to one (in relation to engine cycles). For example, at a 50 percent decay rate, the 1.5 transient fuel factor would be 1.25 on the following engine cycle. Correction tables: To adjust for certain variations in conditions and equipment imperfections, correction factors are used. For example, once engine coolant tem- perature drops below 150 degrees, the mixture may need to be richened by a percentage. There are similar opera- tions for barometric pressure, manifold pressure values, etc. BOI (Beginning Of Injection): This is when the fuel injector starts spraying in relationship to the crank position. In simple terms, BOI is how early the EFI sprays fuel. It’s similar to ignition timing, but with fuel. Rev limit: Factories don’t want you messing with this, but it can make a big power difference on 250Fs. Dwell timing: This is how long electricity saturates the ignition coil. The coil creates a magnetic field which, when chopped, creates a spike that creates the spark. Different coils from different companies require different amounts of electricity to create equal saturation, so flexibility must be built into the ECU. Too much saturation would drain excess energy from the alternator and system. Voltage output: This is important because the injector, primarily voltage driven, is turned on and off with a solenoid at a predetermined pulse width. Since there can be an electrical delay, opening time of the injector isn’t perfect. A voltage correction factor is used to correct this. For example, when voltage drops, it may add two-tenths of a millisecond to opening time. Pressure regulator: Pressure is kept constant on the motorcycle from zero to wide open, but not sensed by the ECU. It’s controlled by a diaphragm and spring that can wear out over time. Q: WHAT’S THE BEST WAY TO MAKE MAPS? A: Honda offers 96 adjustment points (for fuel and ignition maps each) at adjustable throttle position and rpm values, so deciding where to make changes can be tough. Here are some tips: 1. Making changes in fewer fields, so that it creates more of a spike than a mellow curve on the graph, can make it easier to feel a change by the seat of your pants. Examine the rpm and throttle values, make an intuitive guess and test it out. 2. Advancing the ignition makes the power feel a bit sharper and more aggressive; retarding makes it mellower. 3. Fuel enrichment makes the texture of the power feel fatter, and leaning makes it crisper. To make the 2010 450 feel more aggressive off the bottom, advance and lean the lower fields by one or two points. ;
REPROGRAMMING YOUR 2010 HONDA